Research published by the University of Wisconsin describes a way of generating sufficient electrical energy from human movement to power mobile gadgets.
Tapping into the kinetic energy inherent in, say, walking up the street and converting it into electrical energy is nothing new, but the Wisconsin team, led by Tom Krupenkin …

Waiting for this

Think the other way

Instead of putting the tech into footware put it into the surfaces. Imaging a carpet (or tiles) in busy airport...... how much power could be generated ? True it would be a pain to clean and have a other issues.